BigQueryWriteIntegrationTests.test_big_query_write_without_schema - flaky post commit

Log: https://builds.apache.org/job/beam_PostCommit_Python37/1047/testReport/junit/apache_beam.io.gcp.bigquery_write_it_test/BigQueryWriteIntegrationTests/test_big_query_write_without_schema/

Error Message
Expected: (Expected data is [(b'xyw', datetime.date(2011, 1, 1), datetime.time(23, 59, 59, 999999)), (b'abc', datetime.date(2000, 1, 1), datetime.time(0, 0)), (b'\xe4\xbd\xa0\xe5\xa5\xbd', datetime.date(3000, 12, 31), datetime.time(23, 59, 59)), (b'\xab\xac\xad', datetime.date(2000, 1, 1), datetime.time(0, 0))])
but: Expected data is [(b'xyw', datetime.date(2011, 1, 1), datetime.time(23, 59, 59, 999999)), (b'abc', datetime.date(2000, 1, 1), datetime.time(0, 0)), (b'\xe4\xbd\xa0\xe5\xa5\xbd', datetime.date(3000, 12, 31), datetime.time(23, 59, 59)), (b'\xab\xac\xad', datetime.date(2000, 1, 1), datetime.time(0, 0))] Actual data is []